1. Field of the Invention
The present invention relates to a method and apparatus for pyroelectric emission lithography using a patterned emitter.
2. Description of the Related Art
An apparatus for performing ferroelectric switching lithography, which uses a patterned emitter, emits electrons by switching a patterned ferroelectric emitter to expose an electron resist on a substrate to form a desired pattern which is the same as that of the emitter. Ferroelectric switching emission is disadvantageous in that the electrode formed on the emitter by a mask, absorbs electrons. Moreover, the emitter cannot reliably emit electrons when it is not connected to the electrode.
To solve the above problem, a feature of the present invention includes an apparatus for and method of pyroelectric lithography using a patterned emitter, in which a pyroelectric emitter or a ferroelectric emitter emits electrons when heated in a vacuum by infrared rays, a laser, or a heater. The emitter is patterned by a mask so that electrons emitted from the emitter expose an electron resist on a substrate to form a pattern which is the same as that of the emitter.
An apparatus for pyroelectric lithography according to the present invention comprises a plate type emitter formed of a pyroelectric material; a mask stacked on the plate type emitter in a desired pattern where the mask allows electrons to be emitted from the plate type emitter in a desired pattern; a substrate which carries an object to be etched to form the desired pattern; an electron resist deposited on the substrate where the electron resist is sensitive to the emitted electrons; a heating source for heating the plate type emitter; a power supply for applying a voltage between an emitter structure and the object to be etched to allow the electrons to be emitted from the emitter structure and applied to the object to be etched where the emitter structure comprises the plate type emitter and the mask, and the object to be etched comprises the substrate and the electron resist; and magnets disposed outside the emitter structure and the object to be etched for controlling the path of the electrons emitted from the emitter structure towards the object to be etched.
Preferably, the plate type emitter is formed of a ferroelectric material, the heating source is a remote controlled heater which generates infrared rays or a laser, or a contact heating plate which uses resistance heating. The heating source generates sufficient heat to heat the emitter to its Curie temperature.
There is also provided a method of providing a one-to-one projection of pyroelectric emission lithography comprising forming a plate type emitter of a pyroelectric material; masking the plate type emitter to form a desired pattern that allows electrons to be emitted in a desired pattern; depositing an electron resist on a substrate where the electron resist is sensitive to the emitted electrons; heating the plate type emitter; exposing the substrate to the emitter to form the desired pattern; applying a voltage between the emitter and the object to be etched to allow the electrons to be emitted along a path from the emitter and applied to the object to be etched; and controlling the path of electrons using magnets disposed outside the emitter structure and the object to be etched.
Further, there is also provided an apparatus for an x-to-one projection of pyroelectric emission, which comprises a plate type emitter formed of a pyroelectric material; a mask stacked on the plate type emitter in a desired pattern where the mask allows electrons to be emitted from the plate type emitter in a desired pattern; a substrate which carries an object to be etched to form the desired pattern; an electron resist deposited on the substrate where the electron resist induces the emitted electrons; a heating source for heating the plate type emitter; a power supply for applying a voltage between an emitter structure and an object to be etched to allow the electrons to be emitted from the emitter structure and applied to the object to be etched, the emitter structure comprising the plate type emitter and the mask, and the object to be etched comprising the substrate and the electron resist; and a projection system disposed between the emitter structure and the object to be etched for controlling the path of the electrons emitted from the emitter structure towards the object to be etched.
Preferably, the plate type emitter is formed of a ferroelectric material. The heating source is a remote controlled heater that generates infrared rays or a laser, or a contact heating plate which uses resistance heating. The heating source generates sufficient heat to heat the emitter to its Curie temperature. The projection system includes deflectors for deflecting electrons emitted from the emitter structure; a magnetic lens disposed between the deflectors where the magnetic lens focuses the emitted electrons; and an aperture for passing electrons focused by the magnetic lens and filtering out electrons drifting away from the focused electrons.
In addition, there is provided a method of providing an x-to-one projection of pyroelectric emission lithography comprising forming a plate type emitter of a pyroelectric material; masking the plate type emitter in a desired pattern to allow electrons to be emitted from the plate type emitter in a desired pattern; providing a substrate on which to etch a desired etching pattern; depositing an electron resist on the substrate; heating the plate type emitter; applying a voltage between the emitter and the object to be etched to allow the electrons to be emitted along a path from the emitter and the object to be etched; and controlling the path of electrons emitted from the emitter structure towards the object to be etched using a projection system.
The invention, though, is pointed out with particularity by the appended claims.